OCCURRENCE OF Toxoplasma gondii ANTIBODIES IN SERA FROM DOGS OF THE
URBAN AND RURAL AREAS FROM BRAZIL
SILVIO L.P. DE SOUZA1, SOLANGE M. GENNARI1*, LÚCIA E.O. YAI2, SANDRA R.N. D’AURIA2, SONIA M.S. CARDOSO2,
JOSÉ S. GUIMARÃES JUNIOR3, JITENDER P. DUBEY4
ABSTRACT.- SOUZA S.L.P DE, GENNARI S.M., YAI L.E.O., D’AURIA S.R.N., CARDOSO S.M.S., GUIMARÃES JÚNIOR J.S., DUBEY J.P. Occurrence of Toxoplasma gondii antibodies in sera from dogs of the
urban and rural areas from Brazil. [Ocorrência de anticorpos anti-Toxoplasma gondii no soro de cães de
áreas urbanas e rurais do Brasil.] Revista Brasileira de Parasitologia Veterinária v. 12, n. 1, p. 1-3, 2003. Depto
de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, Cidade Universitária, 05508-000, Brazil. E-mail:
[email protected]
Antibodies to Toxoplasma gondii were detected in serum samples of 1244 dogs from urban and rural areas of
Brazil. The rural (n=134) dogs were from the northern region of Paraná State and the urban (n=1110) were from
the city of SãoPaulo, S.P. The urban dogs were from two different origins, stray dogs (n=610) and owned dogs
(n=500). The samples were analyzed by the modified agglutination test (MAT), using a cut-off value of 1:25.
Antibodies were found in 21.3% (265 of 1244 dogs). The occurrence in the rural and urban dogs was 34.3% (46 of
134 dogs) and 19.7% (219 of 1110 dogs), respectively. Among the urban dogs, 31.6% (193) of 610 stray dogs, and
5.2% (26) of 500 owned dogs had antibodies to T. gondii.
KEY WORDS: Toxoplasma gondii; Antibodies; Modified agglutination test; Brazil.
RESUMO
Amostras de soro de 1244 cães provenientes de áreas urbana
e rural do Brasil foram examinadas para a presença de
anticorpos anti-Toxoplasma gondii. Os cães rurais (134) foram provenientes da região Norte do Estado do Paraná e os
urbanos (1110) da cidade de São Paulo, S.P. Os cães urbanos foram de duas diferentes origens, cães não domiciliados
(610) e domiciliados (500). As amostras foram analisadas
pelo teste de aglutinação modificada (MAT) adotando-se
como ponto de corte 1:25. Anticorpos anti-T. gondii foram
1
Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av.
Prof. Orlando Marques de Paiva, 87, Cidade Universitária, São Paulo, SP, CEP
05508-000, Brazil.
2
Centro de Controle de Zoonoses de São Paulo, Rua Santa Eulália, 86,
Santana, São Paulo, SP, CEP 02031-020, Brazil.
3
Centro de Ciências Agrárias , Universidade Estadual de Londrina, Campus
Universitário, C.P. 6001, CEP 86051-990, Londrina, PR, Brazil.
4
Animal Parasitic Diseases Laboratory, Animal and Natural Resources
Institute, Agricultural Research Service, United States Department of
Agriculture, Building 1001, Beltsville, Maryland, 20705, USA.
*Corresponding author: [email protected] (S.M. Gennari).
encontrados em 21,3% (265 dos 1244 cães). A ocorrência
nos cães rurais e urbanos foi 34,3% (46 dos 134 cães) e 19,7%
(219 dos 1110 cães) respectivamente. Entre os cães urbanos,
31,6% (193) dos 610 cães não domiciliados e 5,2% (26) dos
500 cães domiciliados apresentaram anticorpos anti-T. gondii.
PALAVRAS-CHAVE: Toxoplasma gondii, Anticorpos, Teste de aglutinação modificada, Brasil.
INTRODUCTION
Seroprevalence of Toxoplasma gondii in humans in Brazil
is generally very high (DUBEY; BEATTIE, 1988). São Paulo city is a big metropolitan area with an estimated population
of about 20 millions. Although cats are the only known host
that can excrete the environmentally-resistant oocysts, dogs
were identified as a potential risk factor for T. gondii infection
in humans in Panama (FRENKEL et al., 1995). It has been
proposed that dogs may rollover in infected cat feces and
children may become infected by licking or patting the dog
(FRENKEL; PARKER, 1996; LINDSAY et al., 1997). If this
is true, then dogs themselves may become infected by licking
infected canine fur or cat feces (LINDSAY et al., 1997).
Rev. Bras. Parasitol. Vet., 12, 1, 1-3 (2003)
(Brazil. J. Vet. Parasitol.)
2
Souza et al.
Recently, antibodies to T. gondii were found in 26.7% of 430
domestic cats from the city of São Paulo (SILVA et al., 2002).
Public health considerations have recently prompted a
number of studies on toxoplasmosis particularly in those animal species that have been in close contact with humans for
centuries. The objective of the present study was to
determinate the occurrence of T. gondii antibodies in dogs
from rural and urban areas of Brazil and to evaluate the
differences between owned and stray urban dogs.
MATERIALS AND METHODS
In total serum samples from 1244 dogs were examined
for T. gondii antibodies. Of these, 134 dogs were from 22
dairy cattle farms in the northern region of Paraná State (SOUZA et al., 2002). The remaining 1110 dogs were from the city
of São Paulo. From those 500 were owned dogs and 610 had
been captured from the streets by Center for Zoonosis Control
of São Paulo city (GENNARI et al., 2002). Blood samples
were collected from each animal, and sera were stored at – 20
ºC until serologic analysis.
Sera were tested for T. gondii antibodies by the modified
agglutination test (MAT) using formalin-fixed whole
tachyzoites and 2-mercapthoethanol to destroy IgM and non
specific reactions as previously described (DUBEY;
DESMONTS, 1987). Sera were screened using 1:25 dilution,
and the positives were tested in two more dilutions 1:50 and
1:500. A titer of ³ 1:25 was considered indicative of past T.
gondii infection. Positive and negative controls were included
in each test.
Serum were analyzed at the Animal Parasitic Diseases
Laboratory, USDA, Beltsville, Maryland, and at the Departamento de Medicina Veterinária Preventiva e Saúde Animal,
Faculdade de Medicina Veterinária e Zootecnia, USP, São
Paulo.
RESULTS
Antibodies to T. gondii were found in 265 (21.3%) of 1244
dogs. With respect to origin, antibodies were found in 219
(19.7%) of 1110 urban dogs, 26 (5.2%) of 500 owned dogs,
and 193 (31.6%) of 610 stray dogs. From the rural area, 46 of
134 (34.3%) dogs had antibodies to T. gondii (Table 1).
Table 1. Toxoplasma gondii antibodies in sera of dogs from
urban (owned and stray) and rural area from Brazil.
Group
a
b
Nº of
Nº of
%
Antibody titers
dogs seropositives Positive 25 50 500
(³ 1:25)
Urban owned dogs a 500
Urban stray dogs a
610
Rural dogs b
134
26
193
46
5.2
31.6
34.3
20
96
28
06
91
17
0
06
1
Total
265
21.3
144 114
7
1244
from city of São Paulo, SP
from the northern region of Paraná State
DISCUSSION
It is difficult to compare results of the present study with
others surveys in dogs from Brazil because of the sample size,
period of survey, type of serologic test used, cut-off value for
serology, and type of dog population.
Results of this study indicate that 21.3% of the dogs were
exposed to infection to T. gondii. Dogs generally become
infected with T. gondii by ingesting infected uncooked or
undercooked meat containing tissues cysts or food and water
contaminated with oocysts. Then, infection within the canine
population means that the involved area represents an
ecological niche for the parasite and a potential transmission
risk for humans (GERMANO et al., 1985; JACKSON et al.,
1987; CABRAL et al., 1998). The low occurrence of T. gondii
in owned dogs is of interest indicating that only a small
proportion of dogs in homes in São Paulo had been exposed
to either oocysts or infected meat. The higher occurrence of
T. gondii in rural farm dogs and stray dogs reflects more
opportunities to ingest tissues of animals or oocysts from the
environment.
Svoboda and Svobodová (1987) reported that T. gondii
antibodies were significantly less frequently in dogs kept in
apartments and fed exclusively heat-treated food, and results
of the present study support these conclusions.
Acknowledgements. This study was partially financed
by FAPESP. S. M. Gennari was in receipted of a fellowship
from CNPq and S. L. P. Souza from FAPESP.
REFERENCES
CABRAL, D. D.; SILVA, D. A. O.; MINEO, J. R.;
FERREIRA, F.A.; DURAN, F. P. Frequency of antiToxoplasma gondii antibodies in apparently healthy dogs
of the city of Uberlândia-MG. Brazil. J. Vet. Parasitol. v.
7, p. 87-90, 1998.
DUBEY J. P; BEATTIE C. P. Toxoplasmosis of animals and
man. Boca Raton, FL: CRC Press, 1988. 220 p.
DUBEY, J. P.; DESMONTS, G. Serological responses of
equids fed Toxoplasma gondii oocysts. Equine Vet. J. v.
19, p. 337-339, 1987.
FRENKEL, J. K.; PARKER, B. B. An apparent role of dogs
in the transmission of Toxoplasma gondii. The probable
importance of xenosmophilia. Ann. N. Y. Acad. Sci. v. 791,
p. 402-407, 1996.
FRENKEL, J. K.; HASSANEIN, K. M.; HASSANEIN, R.
S.; BROWN, E.; THULLIEZ, P.; QUINTERO-NUNEZ,
R. Transmission of Toxoplasma gondii in Panama City,
Panama: a five-year prospective cohort study of children,
cats, rodents, birds, and soil. Am. J. Trop. Med. Hyg. v. 53,
p. 458-468, 1995.
GENNARI, S. M.; YAI, L. E. O.; D’ÁURIA, S. N. R.; CARDOSO, S. M. S.; KWOK, O. C. H.; JENKINS, M. C.;
DUBEY, J. P. Occurrence of Neospora caninum antibodies
in sera from dogs of the city of São Paulo, Brazil. Vet.
Parasitol. v. 106, p. 177-179, 2002.
Rev. Bras. Parasitol. Vet., 12, 1, 1-3 (2003)
(Brazil. J. Vet. Parasitol.)
Occurrence of Toxolasma gondii antibodies in sera from dogs of the urban and rural areas from Brazil
GERMANO, P. M. L.; ERBOLATO, E. B.; ISHIZUKA, M.
M. Estudo sorológico da toxoplasmose canina, pele prova
de imunofluorescência indireta, na cidade de Campinas,
1981. Rev. Fac. Med. Vet. Zootec. Univ. São Paulo v. 22,
p. 53-58, 1985.
JACKSON, M. H.; HUTCHISON, W. M.; SIIM, J. C.
Prevalence of Toxoplasma gondii in meat animals, cats and
dogs in central Scotland. Br Vet. J. v. 143, p. 159-165, 1987.
LINDSAY, D. S.; DUBEY, J. P.; BUTLER, J. M.; BLAGBURN,
B. L. Mechanical transmission of Toxoplasma gondii oocysts
by dogs. Vet. Parasitol. v. 73, p. 27-33, 1997.
SILVA, J. C. R.; GENNARI, S. M.; RAGOZO, A. M. A.;
3
AMAJONES, V.R.; MAGNABOSCO, C.; YAI, L. E. O.;
FERREIRA NETO, J. S.; DUBEY, J.P. Prevalence of Toxoplasma gondii antibodies in sera of domestic cats from Guarulhos
and São Paulo, Brazil. J. Parasitol. v. 88, p. 419-420, 2002.
SOUZA, S. L. P.; GUIMARÃES, J. S.; FERREIRA, F.;
DUBEY, J.P.; GENNARI, S. M. Prevalence of Neospora
caninum antibodies in dogs from dairy cattle farms in
Parana, Brazil. J. Parasitol. v. 88, p. 408-409, 2002.
SVOBODA, M.; SVOBODOVÁ, V. Effects of breed, sex,
age, management and nutrition on the incidence of
Toxoplasma gondii antibodies in dogs and cats. Acta Vet.
Brno, v. 56, p. 315-330, 1987.
Received on November 12, 2002
Accepted for publication on June 10, 2003.
Rev. Bras. Parasitol. Vet., 12, 1, 1-3 (2003)
(Brazil. J. Vet. Parasitol.)